The present invention relates to a punching and shearing machine with variable cutting angle.
Punching and shearing machines are known having a structure essentially consisting of a box-like supporting frame. The actuation elements of the shearing parts are coupled to the frame so as to provide a set pivoting point for a good operation of the machines. For some workings these machines can furthermore be provided with a group of blades (upper and lower ones) to vary the cutting angle as required. The blades are mounted on supports rotating relatively to one another along arcs of circles.
Finally, all shearing and punching machines share the common problem of defining the applicable shearing force and of keeping constant the required play between the upper blades and the lower blades, the extent of said play being always very limited and, indicatively, in any case of the order of tenths or hundredths of a millimeter.
Known machines have considerable disadvantages as to their general construction: in fact they must necessarily be completely supported by the above described box-like structures, thus making maintenance and/or general and partial disassembly operations extremely complicated and troublesome.
These known machines furthermore have mostly manually actuated devices for determining the applicable forces and for adjusting the play between the blades, their precision therefore depending on the experience of their operator.
Finally, the devices for varying the cutting angle are constructively very complicated and are not easy to operate.